Kinnear J.E.,Number 9 Valley Road |
Krebs C.J.,University of Canberra |
Pentland C.,Edith Cowan University |
Orell P.,Environmental Management Branch |
And 2 more authors.
Wildlife Research | Year: 2010
Predation is widely believed to be the main threatening process for many native vertebrates in Australia. For 25 years, predator-baiting experiments have been used in the Western Australian Central Wheatbelt to control red fox predation on rock-wallabies and other endangered marsupial prey elsewhere. We review here the history of a series of baiting experiments designed to protect rock-wallaby colonies by controlling red foxes with 1080 poison baits. We continue to support the conclusion that red foxes can reduce or exterminate rock-wallaby populations in Western Australia. Research trials from 1990 to 2008 have uniformly shown a dramatic recovery of rock-wallaby populations once red foxes are baited. Baiting experiments are often black boxes and their success should not blind us to their weaknesses. Ideally, what we would like to measure are the functional responses of predators to prey abundance directly. As a contribution towards this goal, we describe new technology that enables one to determine which predator killed which prey, at exactly what time, with improved research and management outcomes. © CSIRO 2010. Source
Joosse P.J.,Environmental Management Branch |
Baker D.B.,Heidelberg University
Canadian Journal of Soil Science | Year: 2011
Over the past decade, scientists have been discussing the re-emergence of harmful algal blooms and excessive growth of Cladophora in some areas of the Great Lakes. An observation that has emerged from these discussions is that management of non-point or diffuse sources of phosphorus will be more important in the future in order to address symptoms of eutrophication in the nearshore. This paper provides context for this renewed focus on managing non-point source tributary loads and is based primarily on materials and discussions from the Great Lakes P Forum. There are changes that have occurred in the lakes and tributaries in the past 15 yr that indicate a greater need to focus on non-point sources, whether urban or rural. Changes have also occurred in land management to reduce non-point P losses from agriculture. While these changes have reduced sediment and particulate P loading in some Ohio tributaries, the more bioavailable, dissolved P forms have increased. As there is incomplete knowledge about the mechanisms that are influencing algal growth, it could be a challenge to demonstrate, in the near term, improvements in water quality with further P reductions from agriculture alone. Regardless, there appears to be a desire for improved accountability and transparency for agricultural non-point source P management. Source
Anderson C.R.,University of California at Santa Cruz |
Anderson C.R.,University of South Carolina |
Kudela R.M.,University of California at Santa Cruz |
Benitez-Nelson C.,University of South Carolina |
And 6 more authors.
Geophysical Research Letters | Year: 2011
An apparent link between upwelling-related physical signatures, macronutrients, and toxic diatom blooms in the various "hotspots" throughout California has motivated attempts to forecast harmful algal blooms (HABs) as a function of select environmental variables. Empirical models for predicting toxic Pseudo-nitzschia blooms in one such region, the Santa Barbara Channel (SBC), are tested in a nowcast mode using predictions based on merging data from MODIS ocean color geophysical products and the Regional Ocean Modeling System (ROMS) applied to the Southern California Bight. Thresholds for each model generate event forecasts. Spatially-explicit, monthly HAB maps are compared to shipboard observations and California monitoring data, demonstrating that the models predict offshore events otherwise undetected by nearshore monitoring. The use of mechanistic hydrodynamic models in concert with empirical, biological models facilitates future process studies on the effects of coastal eutrophication and climate change on regional HAB dynamics. Copyright © 2011 by the American Geophysical Union. Source
Hecht A.D.,U.S. Environmental Protection Agency |
Fiksel J.,U.S. Environmental Protection Agency |
Fulton S.C.,U.S. Environmental Protection Agency |
Yosie T.F.,World Environment Center |
And 4 more authors.
Sustainability: Science, Practice, and Policy | Year: 2012
Although the world faces serious environmental, economic, and social challenges, we believe that a combination of science and innovation, effective governance, and public-private collaboration can help to overcome many of them and achieve sustainable development. Numerous government policies are now promoting sustainable management practices, while many people in the business and financial communities view sustainability as a means to reduce long-term risk, enhance competitiveness, and promote social well-being. Advances in science and technology are creating new economic opportunities and producing sustainable solutions, while expanded public access to global data and information is helping to shape business and government policies. Looking ahead, sustainability will be best pursued by building on these trends and encouraging new collaborative initiatives among governments, businesses, and the nonprofit sector. This article is an example of a collaboration that includes government, business, academic, nongovernmental, and international organizations. © 2012 Gram-Hanssen & Christensen. Source
Adams J.R.,University of Guelph |
Adams J.R.,Agriculture and Agri Food Canada |
Rowlandson T.L.,University of Guelph |
McKeown S.J.,University of Guelph |
And 3 more authors.
Canadian Journal of Remote Sensing | Year: 2013
This study evaluates the utility of the Cloude-Pottier and Freeman-Durden scattering decompositions for providing agricultural land surface information during autumn months using C-band polarimetric RADARSAT-2 data. We applied these decompositions over 94 agricultural fields in Southern Ontario, Canada, to characterize scattering mechanisms from unharvested senesced crops and harvested fields with three generalized soil tillage practices. The decompositions were applied to RADARSAT-2 images over six dates during October and November 2010 at high (49°) and low (23°) incidence angles. Agreement was found between the decompositions for the identification of primary (volume and rough surface scatter) scattering mechanisms for the senesced unharvested crops and the harvested fields. Significant statistical separability was observed between the strengths of decomposition parameters when comparing (i) senesced unharvested crops to post-harvest conventional tillage fields and (ii) post-harvest no tillage fields to post-harvest conventional tillage fields. These results suggest that high accuracy classifications may be possible with these data; however, weak separability was observed when comparing fields with conservation tillage. The strongest separability was observed with Entropy and α-angle of the Cloude-Pottier decomposition and the rough surface scattering component of the Freeman-Durden decomposition, suggesting sensitivity of these parameters to surface roughness and crop residue. Results also demonstrated that superior separability was found with the data at the higher 49° incidence angle in contrast to data acquired at the lower 23° incidence angle imagery. © 2013 CASI. Source